A transaction model for multiagent production systems communicating through shared working memory is proposed. To realize arbitrary interleaved rule firings of multiple agents, each transaction is formed when a rule is selected for firing. An efficient concurrency control protocol, called the lazy lock protocol, is introduced to guarantee the serializability of rule firings. As a result of allowing interleaved rule firings, however, ensuring the serializability becomes no longer enough to guarantee the consistency of the shared working memory. A logical dependency model and its maintenance mechanisms are thus introduced to overcome this problem.